Iraq's prime minister, Haider al-Abadi, called the destruction of the mosque an "official declaration of defeat" by IS. ...The explosions happened as Iraq's elite Counter Terrorism Service units, which have been battling their way through Mosul's Old City, got within 50 metres of the mosque, the statement said. ...Al-Baghdadi proclaimed himself "caliph," or ruler of all Muslims, from the pulpit of the mosque on 4 July 2014, after the group's fighters overran parts of Iraq and Syria.